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                                                                    EXHIBIT 10.8

THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.
IT MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF REGISTRATION OR AN EXEMPTION
THEREFROM UNDER SAID ACT.

                             SECURED PROMISSORY NOTE

$492,500                                                       February 1, 2000

         FOR VALUE RECEIVED, the undersigned (the "Payor") hereby promises to
pay to the order of Empi Corp., a Minnesota corporation (the "Payee" or the
"Company"), the principal amount Four hundred ninety-two thousand five hundred
Dollars ($492,500) (the "Principal Amount"), together with interest accrued
thereon, calculated and payable as set forth below in this Note.

         As security for the performance of his obligations herein, Payor has,
contemporaneously with this Note, entered a Stock Pledge and Security Agreement
dated as of the date hereof between Payor and Payee (the "Pledge Agreement" and,
together with this Note, the "Loan Documents").

         1. Certain Defined Terms.

         For the purposes hereof, the following terms shall have the following
meanings:

            1.1 "Affiliate" of any specified Person means any other Person (i)
which directly or indirectly through one or more intermediaries controls, or is
controlled by, or is under common control with, such specified Person, (ii)
which beneficially owns' or holds 15% or more of any class of the Voting Stock
or other equity interest of such specified Person or (iii) of which 15% or more
of the Voting Stock or other equity interest is beneficially owned or held by
such specified Person or a Subsidiary of such specified Person. For the purposes
of this definition, "control" when used with respect to any specified Person
means the power to direct the management and policies of such Person directly or
indirectly, whether through the ownership of Voting Stock, by contract or
otherwise; and the terms "controlling" and "controlled" have meanings
correlative to the foregoing.

            1.2 "Capital Stock", with respect to any Person, means any capital
stock or membership interests of such Person, regardless of class or
designation, and all warrants, options, purchase rights, conversion or exchange
rights, voting rights, calls or claims of any character with respect thereto.

            1.3 "Carlyle" means T.C. Group, L.L.C., a limited liability company
organized under the laws of the State of Delaware.

            1.4 "Carlyle Investors" means the Persons which are members of MPI
Holdings, L.L.C., a Delaware limited liability company, as of August 31, 1999.

            1.5 "Commission" means the Securities and Exchange Commission and
any Governmental Authority succeeding to the functions thereof.

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            1.6  "Final Payment Date" has the meaning set forth in Section 2.3.

            1.7  "Governmental Authority" means any nation or government, any
federal, state, local or other political subdivision thereof and any
governmental entity exercising executive, legislative, judicial, regulatory or
administrative functions of or pertaining to government.

            1.8  "Liquidity Event" means the first occurrence of the sale,
transfer, conveyance or other disposition, in one or a series of related
transactions, of the debt and equity securities of Parent held by the Principal
Stockholder such that immediately following such transaction (or transactions),
the value (at original cost) of all debt and equity securities of Parent held by
the Principal Stockholder is less than 20% of the value (at original cost) of
the debt and equity securities of Parent held by the Principal Stockholder as of
August 31, 1999.

            1.9  "Parent" means Empi, Inc., a Minnesota corporation, the parent
of the Company.

            1.10 "Person" means any natural person, corporation, limited
partnership, limited liability company, general partnership, joint stock
company, joint venture, association, company, trust, bank, trust company, land
trust, business trust, or other organization, whether or not a legal entity, and
any Governmental Authority.

            1.11 "Principal Stockholder" means, collectively, MPI Holdings,
L.L.C. and any of its Permitted Assignees (as such term is defined in that
certain Shareholder Voting and Control Agreement by and among the Company, GE
Capital Equity Investments, Inc. and UPI Holdings, L.L.C.).

            1.12 "Securities" means any stock, shares, voting trust
certificates, bonds, debentures, notes or other evidences of indebtedness,
secured or unsecured, convertible, subordinated or otherwise, or any
certificates of interest, shares or participation in temporary or interim
certificates for the purchase or acquisition of, or any right to subscribe to,
purchase or acquire any of the foregoing.

            1.13 "Securities Act" means the Securities Act of 1933, as amended
from time to time, and any successor statute.

            1.14 "Shares" has the meaning set forth in Section 2.2.

            1.15 "Subsidiary" of a Person means any corporation or other entity
of which equity Securities or other ownership interests having ordinary voting
power to elect a majority of the board of directors or other persons performing
similar functions are the time directly or indirectly owned or controlled by
such Person, one or more of the other subsidiaries of such Person or any
combination thereof.

            1.16 "Voting Stock" means, with respect to any Person, securities
with respect to any class or classes of Capital Stock of such Person entitling
the holders thereof (whether at all times or only so long as no senior class of
stock or membership interest has voting

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power by reason of any contingency) to vote in the election of members of the
board of directors or management committee of such Person.

        2.  Payment of Principal and Interest.

            2.1 Calculation and Payment of Interest. Interest on the principal
balance of this Note outstanding from time to time until paid in full shall
accrue at the rate of 9.0% per annum, computed on the basis of a 365 or 366 day
year, as appropriate, for the actual number of days elapsed, commencing on the
date hereof for this Note.

            2.2 Mandatory Payments of Principal Prior to Final Payment Date. At
any time that a distribution of cash is made by Parent to Payor in respect of
any shares of common stock, par value $0.01 per share, of Parent then held by
Payor (the "Shares"), Payor shall immediately thereupon make a payment on this
Note equal to the total amount distributed up to the Principal Amount, together
with all accrued and unpaid interest thereon, then outstanding. In the event
that (x) Payor sells or transfers, or purports to sell or transfer, all or any
portion of the Shares, or the Shares are converted into the right to receive any
consideration other than shares of capital stock of a successor in interest of
Parent, (y) Payor ceases to be an employee of Parent and its Subsidiaries other
than as a result of death, disability or retirement, or (z) Payor, at any time
after the date hereof is employed by or works as an independent contractor
providing services to, or as a consultant for, any competitor of Parent or any
of its Subsidiaries (as determined in good faith by the Board of Directors of
the Company), the Principal Amount, together with all accrued and unpaid
interest thereof, shall immediately be due and payable.

            2.3 Final Payment Date. Unless earlier repaid in full as a result of
mandatory payments of principal pursuant to Section 2.2 hereof, the Principal
Amount and any accrued interest thereon, and all other amounts as may be due
hereunder shall become due and payable upon the earlier to occur of: (A) the
eighth anniversary of the date hereof, or (B) a Liquidity Event (the "Final
Payment Date").

            2.4 Prepayment. Payor may at his or her option, at any time, without
premium or penalty, prepay all or any portion of the Note.

            2.5 Remedies on Default. Upon the occurrence of an Event of Default
(as defined below), Payee may (a) declare the Principal Amount to be due and
payable, whereupon the Principal Amount and any accrued interest thereon and all
other amounts as may be due hereunder shall become immediately due and payable,
without presentment, demand, protest or notice of any kind, all of which the
Payor hereby expressly waives; and (b) exercise any and all rights and remedies
available to it at law or in equity or under any of the Loan Documents,
including without limitation judicial or non judicial foreclosure or public or
private sale of any of the Collateral (as defined in the Pledge Agreement)
pursuant to the Pledge Agreement. No delay or omission of the Payee to exercise
any right under the Loan Documents shall impair such right or be construed to be
a waiver of any Event of Default or an acquiescence therein. Any single or
partial exercise of any such right shall not preclude other or further exercise
thereof or the exercise of any other right. All remedies contained in the Loan
Documents or afforded by law shall be cumulative and all shall be available to
the Payee until all obligations of Payor hereunder and under the other Loan
Documents have been paid in full.

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        3.  Events of Default.

        In this Note, "Event of Default" means the occurrence of any of the
following:

            3.1 Failure to Make Payments. Payor shall fail to pay, in accordance
with the terms of this Note or any other Loan Document, any amount then due and
owing by Payor hereunder or under any other Loan Document upon the date that
such sum is due.

            3.2 Breach of Terms of Loan Documents. Any of the representations or
warranties made by Payor in any of the Loan Documents shall have been false or
misleading in any material respect or Payee shall fail to perform or observe any
covenants or obligations set forth in any of the Loan Documents (and such
failure shall continue unremedied for a period of thirty days after Payee
becomes or is made aware thereof).

            3.3 Security. The Pledge Agreement shall, except as a result of the
acts or omissions of Payee or any change in applicable law, in any material
respect fail to provide the Payee the security interest, rights, title,
remedies, powers or privileges intended to be created thereby, shall cease to be
in full force and effect, or the validity thereof or the applicability thereof
to the Note, or any other obligations purported to be secured or guaranteed
thereby, or any part thereof shall be disaffirmed by or on behalf of Payor. In
the event of such a change in applicable law, Payor shall take such actions as
may reasonably be requested by the Company, including, without limitation,
entering into such amendment of the Loan Documents as may be necessary to
provide the Payee the security interest, rights, title, remedies, powers or
privileges as are intended to be created by the Pledge Agreement.

            3.4 Insolvency of Payor. Payor shall become insolvent or shall be
unable to pay his debts as they fall due.

        4.  Recourse.

            In the event of default in payment under this Note, Payee shall have
recourse first against the Collateral, and second, against the other assets of
Payor to the full extent of the accreted value of this Note.

        5.  Place of Payment and Notices.

            5.1 Place of Payment. All payments on this Note shall be paid in
lawful currency of the United States of America at the address of the Payee set
forth for notices in Section 5.2, or such other place as may be specified by the
Payee from time to time or otherwise as Payee distributes to Payor.

            5.2 Notice. Any notice or other communication required or permitted
to be given hereunder shall be in writing, and shall be delivered to the parties
at the addresses set forth below (or to such other addresses as the parties may
specify by due notice to the others). Notices or other communications given by
certified mail, return receipt requested, postage prepaid, shall be deemed given
three (3) days after the date of mailing. Notices or other communications set in
any other manner shall be deemed given only when actually received.

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                            Payee:      Empi Corp.
                                        c/o The Carlyle Group
                                        1001 Pennsylvania Avenue, N.W.
                                        Suite 200 South
                                        Washington, D.C. 20004

                            Payor:      Patrick D. Spangler
                                        Empi Sales Corp.
                                        599 Cardigan Rd.
                                        St. Paul, MN 55126

        6.  Usury.

        Nothing contained in this Note shall be deemed to establish or require
the payment of a rate of interest in excess of the maximum rate legally
enforceable. If the rate of interest called for under this Note at any time
exceeds the maximum rate legally enforceable, the rate of interest required to
be paid hereunder shall be automatically reduced to the maximum rate legally
enforceable. If such interest rate is so reduced and thereafter the maximum rate
legally enforceable is increased, the rate of interest required to be paid
hereunder shall be automatically increased to the lesser of the maximum rate
legally enforceable and the rate otherwise provided for in this Note.

        7.  Miscellaneous.

        Each right, power or remedy of Payee under this Note or under applicable
law shall be cumulative and concurrent, and the exercise of one or more of them
shall not preclude the simultaneous or later exercise by the Payee of any or all
of such other rights, powers or remedies. No modification, change, wavier or
amendment to this Note shall be deemed to be made unless in writing signed by
the party to be charged. If it becomes necessary to employ counsel to collect
this obligation, the Payor agrees to pay reasonable attorneys' fees for legal
services involved. This Note may not be assigned by Payor without the prior
written consent of Payee in its sole discretion. The Payor and each endorser,
guarantor, accommodation party, and surety of this Note hereby waives demand,
presentment for payment, protest, notice of dishonor and notice of protest. This
Note shall inure to the benefit of and be binding upon the parties and their
respective successors and assigns. The invalidity, illegality or enforceability
of any of the provisions of this Note shall not effect or impair the validity,
legality or enforceability of any other provision. This Note shall be deemed to
be made in, and shall be governed by the laws of, the State of Minnesota.

                            [Signature Pages Follow]

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Dated: February 1, 2000              PAYOR


                                     By:______________________________
                                        Patrick D. Spangler

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                                 Acknowledgement

        Empi Corp., Payee under the attached secured Promissory Note, dated as
of February 1, 2000 (the "Note") hereby acknowledges the provisions of this Note
and agrees to be bound by the provisions thereof.

                                        EMPI CORP.


                                        By:_______________________________
                                           H. Philip Vierling
                                           President & Chief Operating Officer

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